python client
First
send mail
newMail
to-do
new
Merge branch 'one' of github.com:SE-stlzh/gmail-attachment-manager
add the Manifest.json and image
add img file and delete the unuse file
send with existing attach, trash/untrash/delete mail
showEmail
update refresh()
roll back
synchronize maillist
multi-thread
Revert "multi-thread"

This reverts commit a0ca543d273af77258ecdc63c0a2274ad8fe2c46.
multi thread
add date
sort maillist
improve UI